Gas-engine.



G. GEHRANDL GAS ENGINE.

APPLICATION FILED JULY 24,1912

1 1 14, 1 32. Patented Oct. 20, 1914.

3 SHEBT S SHEET 1.

Qliiinesses M fq G. GEHRANDT.

GAS ENGINE.

APPLICATION TILED JULY 24,1912.

1,1 14,1 32. Patented 001. 20, 1914.

3 SHEETS-SHEET 2.

Inve rad 0r. fiwm 5W G. GEHRANDT.

GAS ENGINE.

I APPLICATION FILED JULY 24, 1912.

Wily.

InVen/or:

Patented Oct. 20, 1914.

3 SHEETS-SHEET 3.

lEi

GUSTAV GEHRANDT, OF CHICAGO, ILLINOIS.

GAS-ENGIN E.

Specification of Letters Patent.

Patented (let. 2b, 1914i.

Application filed July 24, 1912. Serial No. 711,367.

To all whom it may concern:

Be itknown that I GUSTAV GEI-IRANDT, a subject of the Emperor of Germany, and a resident of Chicago, Illinois, have invented certain new and useful Improvements in GaslEngines, of which the following is a specification.

The essential object ofthis invention is to provide a gas engine of the rotary type, neaning an engine of that type in which the explosive force of the gas causes continuous rotary movementof a shaft. In this invention the shaft, in addition to the continuous rotary movement, also reciprocates longitudinally of its axis, but this longitudinal reciprocatory movement is not necessarily communicated to the machinery to be driven by the engine.

in the drawings, Figure l is a longitudinal elevation of the engine, the outer casing and some of the other parts being shown in section: Fig. 2 is a view partly in section and partly in elevation taken approximately on the lines Q--Q, Fig. 1 looking toward the right in said figure; l Sis a view partly in section and partly in elevation showing the arrangement for permitting inlet into and outlet from the explosion chan'iber; Fig. l is a section on the line 4l4, Fig. 3; Fig 5 is an end elevation of the member yupon which the explosive force of the gas is eX- er'ted; Fig. (5 a view taken at an angle of 90 degrees to the view shown in Fig. 5; Fig. '7 is a view of one of the cams by which the valves are controlled Fig. 8 is a view of the oth r or companion cam; and Fig. 9 is a side riew depicting alike the members shown in Figs. 7 and 8.

To the Slltl'fl 1, all moving parts except the valves are-connected. Said shaft receives a continuous rotary movement from the operation of the engine and likewise a longitudinal reciprocatory niven'ient. The shaft 1 passes through casting or shell 2, said casting 2 being provided with a central cylindrical opening- 3, through which the shaft passes. The rotating piston 4, upon which the explosive force of the gas is exerted, is secured to said shaft and is provided with a cen'tralg erforation through which. the shaft 1 passes, the shaft being secured to said member l at by a splined collar 6, or any similar device. The member 4 is firmly fixed upon the shaft 1 and the movements of said member 4, whether rotary or longitudinal, are communicated to the shaft.

Said member 4 is adapted to co-act and cooperate with the casting 2 and to receive the impact or force of the explosions f the gas Within said member 2; and the adjoining or abutting faces of the casting 2 and the piston l are, as will hereinafter appear, similarly sha 38d. I

That ace of the member l, which is turned toward the casting 2, is not flat nor perpendicular to the axis of the shaft 1, but is shaped as shown in the drawings, particularly in Figs. 1, 5, and 6. Said piston t is provided with two faces 7 which rise gradually like the threads of a screw in a spiral form. The lefthand edge 8 (Fig. 6) of one face is connected to the right-halal edge 9 of the other spiral face by the beveled surface 10, there being, obviously, two beveled surfaces 10 and two spiral faces 7." upon the piston 4. That face of the listing 2 which is turned toward the rotarypiston l is shaped so as to correspond with said rot ating piston, and said casting is provided with. the two spiral faces 11 connected by beveled surfaces 12.

The casting 2 is contained within an outer shell or casing 13, it being umlerstood that both the casing 13 and the member 2 are non-rotatable. The rotary piston 4 is received within the casing 13, the periphery of said member 4 being provided with a plu rality of circumferential grooves 1% within which strips 15 of packing are received. Said casing 13 is provided with a head 16, which head has a raised seat or channel l? which is received within the circular groove 18, which is upon that side of the rotating piston opposite to the spiral faces 7. it packing gland or stuffing box 16 is provided at the point where shaft 1 passes through the head 16:

Secured upon the shaft 1 is a cam-like member 19, one face of which is made to correspond in shape with the rotating piston 4-, although for convenience faced in the opposite direction, and said member 19 cooperates and coach; with a similarly shaped member 20 which is perforated so that the shaft 1 may pass therethrough, said menibcr 20 being provided with a flange 21 through which bolts 22 pass into the bed The member 20 is fixed, while the member 19 is revoluble. Said bed 23 serves as a hub 1 for the pulley 24 which is connected by pins or bolts 25 to the cap 26, which cap is out-. side of the thing 21 and which secured to shaft 1 at 27 by the nut or binder 28, and hence the shaft 1 and the pulley 24 must rotate in unison. The pins 25 pass through perforations 29 in the spokes of the pulley 24, thus permitting the cap 26 and the pins 25 to move longitudinally with respect to the pulley, although compelling said members to rotate together hence, if a belt be passed over the pulley 24 and said belt be caused to rotate by any suitable means, the rotation of said means will be communicated to the shaft 1, or vice versal The beveled face 2 of the casting 2 is provided with sever l perforations 30, and the spiral face 11 of said casting is likewise perforated at 31. As the rotating piston 4 moves, it travels as indicated by the arrows A. Starting from the position shown in Fig. 1, the rotating piston 4 moves to a point where each beveled face 10 engages the corresponding beveled face 12 on the casting 2, the edges 8 of the rotating piston seating in the crotches 12 which form the junction between one spiral face 11 and a beveled face 12, and the edges 9 of the rotating piston engaging the edges 32 which are the junctions between the other spiral face 11 and the same beveled face 12. After the explosion within the casting 2, the heated gases pass through the ports 30 and bear against the beveled faces 10 and thus cause the rotating piston to move, each spiral face 7 of the rotating piston 1 riding over and upon one of the spiral faces 11, which movement continues until the parts have reached substantially the position depicted in Fig. 1 of the drawings, after which the edges 8 will ride over the edges 32, and the movement just described will be repeated. As the beveled face 10 isforced away from the face 12, the gases which cause that movement, gradually fill the space bound by the faces 7, 10, 11 and 12, but finally make their exit through the ports 31. Partitions 33 divide the interior of each half of the casting into two cavitiesor chambers, and the gas explodes in the chamber 3i which is bounded by the. partition 33 and the beveled face 12. After exploding within the chamber 34, the gases force their way out of said chamber through the ports 30 so as to bear against the beveled faces 10 upon the rotating piston, and having thus acted to drive the machine, the gases make their exit through the ports 31, thence into the chamber 35; from whence they escape through the exhaust pipe 36.

The gas from the city mains or other suitable source of supply is communicated to the pipes 37, which pipes lead into the chainbers or recesses 38. From the gas-receiving chamber 38, the port 39 leads into the ignition chamber 34. Said port 39 is adapted normally to be closed by the valve 39, which valve is carried upon the stem 40, and said stem 40 is normally pressed away from the shaft 1 by the helical spring ll. The stem 4:0 is connected to the cap-like cylinder l2 which reciprocates within the shell-4:3. Each ignition of gas within the chamber 34: will, obviously, tend to cause the valve 39 to seat more firmly and thus shut off the supply of gas, and it is only when the valve is positively unscated by those members operating upon the valvestem 10 that the gas is admitted to the interior of the chamber 34. The shell l3 is slotted at 44; and air from the atmosphere is drawn by the suction of the gas through the slots at and into the interior 45 of the shell. The valve 39, in addition to closing the ports 39 through which the gas passes into the chamber 34:, serves the additional function of shutting off the supply of air from the chamber 34, but when the valve 39 is unseated to permit the entrance of gas, the admission of air is likewise permitted, and because of the fact that the opening or channel through which the air enters into the ignition chamber 34: is so very ll'lllCll larger than the channel 39 through which the gas enters, it is certain that at all times there will be an abundant supply of air within the chamber 3% whenever an ignition is to take place, and it is not necessary to provide any pump or other air-feeding device to force the air into the ignition chamber 34.

The chamber 35 into which the gases pass after the ignition and after driving the rotary piston l, entrance to said chamber bein' allowed through the ports 31, is connccte with an exhaust port 4(3 normally closed by a valve at? similar in construction and open ation to the valves 39. \Yhen the valves l7 are seated, the gases cannot escape, but when the valves are unseated the gas is permitted to pass out through the ports l6 and through the pipes 36 which are connected therewith. All of the valves 39 and l7 are controlled. by substantially the same mechanism and are unseated only when positively forced toward the shaft 1. Each shell or pipe within which any particular valve 39 or 47 happens to be contained is provided with a bracket 18 upon which an arm l9 is pivoted at 50. Each arm 19 is provided with a notched end 51 which rests upon the cap or stud 52 which is connected to the valve-stem 410 or to the val vestem which carries a valve -17. Bracket 53 bears an arm 5i which is adapted to rest upon the member 49, and, when the member al which is pivoted at is caused to rock upon its pivot, the member 49 is obviously rocked upon its own pivot 50, and the valve is thereby unseated. The arm 5 1- is in effect a lever which is fulcrumed at 5.3 and one end of said lever is confiectdtl at 5(3 to the pitman 57. If preferred, the lever Til may be made in two pieces, each keyed or secured to the member 55 which thus acts as a small rockshaft, this being the construction shown at the bottom of Fig. 2 of the drawings. The pitman 57 may be made in one piece or it may be made as shown in Fig. 2, in which said pitman is made in two parts, each secured to a head 58 of a threaded bolt, the two bolts being connected by a take-up sleeve 59, this construction permitting a very accurate adjustment of the parts. At the end nearest the shaft 1, each pitman 57 bears a roller 60.

As best shown in the left-hand end of Fig. 1, a hub 61 is splined upon the shaft 1. Said hub receives the rotary movement of the shaft but since the hub 61 is not rigidly fixed upon the shaft, the spline and feather arrangement permits the shaft to reciprocate longitudinally without communicating i any longitudinal motion to the hub 61; yet at the same time the shaft and hub necessarily rotate, in unison. To said hub the cams 62 and 63 are bolted at 64. The cam-like proistration with the similar projection 66 upon the cam 63. The various pitmen 57 are so located that those pitmen which actuate the mechanism for controlling the valves 39 which permit the access of gas and air are actuated by the cam 62; whereas, those pitmen which operate the valves 47 are controlled by the cam 63. The respective parts are so arranged that when an edge 8 of the rotating piston has moved just beyond the exhaust ports 31, the valves 39 will be unseated, thus permitting the gas and air to pass through the chamber 34. As soon as edge 8 of rotary piston 4 rides over the crest or edge 32 of the casting 2 within which the ignition chamber is contained, the piston 4 will begin to reciprocate toward the left, Fig. 1. Obviously, the unseating of the valves 39 permits air and gas to enter the chamber 34, and this mixture of air and gas will tend to pass through the ports 30 and into the space between the spiral faces 7 and 11; but as the piston continues to move toward the left, Fig. 1, the gas and air mixture is forced backwardly through the ports 30 and is compressed within the ignition chambers 34. The projections 65 are of such size and extend through only so many degrees of are as will permit the right amount of gas and air to enter the chamber, but after any wheel or roller 60 has ridden off the projection 65, the helical spring 41 which encircles the valve-stem upon which the valve 39 is gnounted. will seat said valve. The operation of the valves is so timed that the valves 39. which are unseated at the instant that the edge 8 clears the exhaust ports 31. are seated again just the edge 8 rides over the crest 32, and when the gases are being compressed by the movement of the rotary piston toward the left in Fig. 1, the valves 39 will be and will remain closed. A suitable sparking device (not shown) is provided, and the operation of this spa-rker is so timed that ignition of the compressed gases within the chambers 34 will take place as soon as the beveled faces 10 are in full engagement with the beveled faces 12 'or at the very instant that the edges 8 seat in the crotches 12*. When the rotary piston has advanced to a point where the full force of the exploded gases has been exerted, the projections 66 upon the cam 63 will actuate those pitmen 57 which control the valves 47 and unseat same, this operation being so timed that valves 47 are unseated and the exhaust passages thereby opened, just as the edge 8 is riding over ports 31. At each revolution of the shaft 1, therefore, the cams 62 and 63 first secure a momentary opening of the valves 39 and then a momentary opening of the valves 47 and this opening and closing of the valves is properly timed as may be necessary by the relative position of the rotating piston 4 and the casting 2.

The machinery which is to be driven by the engine can. be actuated by any suitable mechanical appliance for translating the rotation of shaft 1 into motion of the machinery to be driven by the engine. For example, a belt may pass over pulley It will be evident from an inspection of the drawings and from the foregoing description that the rotating piston has a certain longitudinal reciprocation within the shell 13. The movement of this rotating piston from left to right, Fig. 1, will be caused by the action of the spiral surfaces 7 riding upon the similar spiral surfaces 11, and the piston will continue to move slowly from left to right, (Fig. 1) until such time as each edge 8 has reached a crest or edge 32. The movement of the member 4 from left to right (Fig. 1) will be gradual, but the return movement from right to left will be relativelv quick. In order to expedite the right to left movement, Fig. 1, pipes 71 and 72, controlled. respectively, by valves 73 and 74, are connected to the interior. of the chamber within which the member 4 moves, and pipes 71 and T2 are each connected to a compressed air storage tank (not shown.) The inner surface of the shell or casing 13 is channeled. these channeled portions being flush or in registration with the mouths of pipes 711 and 72 so that the air which passes through said pipes is always permitted to have access to the space 76, which is between the head 16 and the rotating piston 4, regardless of the position of the piston. The channels. in other words, prevent the piston from a ting as a valve to close the mouths of the pipes 71 and 72 when the parts are in the position shown in Fig. 1 of the drawings.

4 &

As the piston continues to move toward the right, Fig. 1, the space 76 gradually becomes very small and is diminished in size until it appears very much as shown in Fig. 1. As the member 4 continues to move toward the right, the air within the tank and the space 7 6 becomes very much compressed and will beunder an exceedingly high pressure, but as soon as each edge 8 has passed over the crest, 32, the air which is thus confined will expand and by its expansion will tend to force the rotating piston toward the left, Fig. 1, and'secure its return to the position where it can be acted upon by the exploding gases.

A pipe 77 controlled by valve 78 permits air to be drawn in from the atmosphere as needed, and by proper manipulation of the valves 73 and 79, the rotating piston can be used as a species of air-pump with which to fill the air tank in the first instance. When the piston moves from right to left it will cause a vacuum, thus drawing air in from the outside, but when the piston moves from left to right it will compress this volume ofair and force the compressed air into the storage tank.

Water for the cooling system can be admitted at 85, making its exit at 86, and lubricant is admitted through pipe 87 As heretofore stated, the member 20 is fixed to the bed of the machine, while member 19 is fixed upon the shaft 1 and moves in unison with the shaft. The member 19 bears the spiral faces 90 which extend through the same number of degrees of are and which are of the same pitch as the spiral faces 7, and said member 19 also bears beveled faces 91 corresponding to the beveled faces 10. b The member 20 is provided with beveled faces and spiral faces to correspond with the member 19, 1t being obvious from the drawings that the spiral faces 90 are upon the right-hand side (Fig. 1) ofmember 19, whereas the spiral faces 7 are upon the left-hand side of the member 4:. Similarly the spiral faces upon the member 20 are on the left-hand side, while the spiral faces 11 upon the casting 2 are upon the right-hand side. The reason for providing and for so constructing the members 19 and 20 is to enable these members to coact with each other and to prevent any premature leftto-right movement of the shaft 1 and parts carried thereupon. Were it not for the coacting cams 19 and 20, the explosive force of the gases within the chambers 34 might be exerted in forcing the rotating piston 4 toward the right, Fig. 1, but because of the co-acting cams 19 and 20, the shaft 1 can not reciprocate toward the right any faster than is permitted by the beveled "faces 90 and 91; hence, the explosive force of the gases within the chambers 84, is so confined as to be exerted upon the beveled faces 10 of the rotating piston and upon those faces alone, and cannot cause any premature leftto-right movement of the shaft 1 or the parts carried thereupon.

The operation of the engine is as follows: When the parts are in the position shown in Fig. 1, the valves 39 will be unseated and the gas and air will be entering the chambers 34, but when the piston has rotated to a very slight extent and the edge 8 has ridden over the crest 32, all parts moving in the direction of the arrows A, Figs. 1, 5, and 6, the valves 39 will be seated, the shaft 1 and all parts mounted thereupon will move toward the left, Fig. 1, until such time as the edge 8 seats in the crotch 12. During this right-to-left movement, the gases are compressed but are ignited and exploded just as the edge 8 seats in crotch 12, and, as the heated and exploded gases pass through the ports 30, they bear against the beveled surfaces 10, and by pressing on said beveled surfaces force same away from the beveled faces 12, and thus cause a partial rotation of the member 4 and the shaft 1. As the rotation of the shaft 1 continues, the cam projections 66 act upon those pitmen 57 which control the valves 17 and unseat said valves momentarily, this operation being timed to occur just as the edges 8 ride over the ports 31, the valves 47 being seated as soon as the edges 8 are clear of. the ports 31. The gases, which have performed their service in causing each partial revolution of the shaft and which are then retained within the space between the spiral faces 7 and 11, pass successively through ports 31, chambers 35, and ports 46, from which they are adapted to escape through the exhaust pipes 36.

The drawings depict an engine in which there are two spiral faces 7 and two beveled faces 10 upon each rotating piston, and two sets each of valves 39 and 47 and the other corresponding parts; hence, at each half revolution of the shaft 1 and the parts borne thereupon the explosive force of the gases is manifested, but it should be understood that the parts, of which two each are shown in the drawings, may be arranged in any desired number. In the particular construction shown in the drawings, however, each half revolution of the shaft 1 successively causes the valves 39 to open and then close after which the gases are ignited, thus communicating energy to the shaft 1 as the gases expand, and then the valves 47 are first opened and then closed, thus allowing the exhaust gases to pass out of the engine.

The members 2, 4, 19, and 20 are gcometrically similar each to the other in the respect that each spiral face on each of said members extends through the same number of degrees of are eacle spiral face on each of the other members and said spiral faces are each and all of the samepitch. The various beveled faces (10, 12, 91, etc.,) are, also, all set at the same angle of inclination to the axis of shaft 1, and each of said beveled faces extends through the same number of degrees of are as every other beveled face. It is obvious, therefore, that, notwithstanding the dilference in diameter between the members 2 and 4 on the oneend, and 19 and 20 on the other, that the spiral faces "7 and 11 will be in engagement for exactly the same length of time as the cooperating spiral faces upon the members 19 and 20, and the beveled faces 10 and 12 will be in engagement with each other for exactly the same length of time as the beveled face 91 is in engagement with the beveled face upon the member 20.

It will be observed that the beveled faces 10 extend through only a few degrees of arc while the spiral faces 11 extend through a great many degrees of are. In that form of the invention shown in the drawings in which there are two beveled faces 10 and two spiral faces 11, the beveled faces will be from three to five degrees, and the spiral faces from one hundred seventy-five to one hundred seventy-eight degrees in size, but these dimensions may be varied according to circumstances. The number of degrees of are through which any beveled face extends will correspond to the pitch at which that face is set.

The successive steps in the operation of .the engine are (1) inlet of the gas mixture;

(2) compression of the gas mixture; (3) explosion and expansion of the gas mixture; and discharge or exhaust of the used gases; and the cycle is completed as many times during the revolution of the main shaft 1 as there are spiral faces upon that shaft. The specific engine depicted in the drawings will complete two cycles'for each revolution of the shaft 1, whereas, in most reciprocating gas engines it necessitates at least one revolution of the main shaft to complete the cycle, but with this invention there will be a'plurality of cycles being completed simultaneously during each revolution of the main shaft.

Although but one specific embodiment of the invention has been shown in the drawings and described in the specification, it is obvious that many changes in details of construction may be made without departing from the scope of the invention or of the various claims.

I claim as my invention:

1. A gas engine comprising a casting and a rotating piston cooperating therewith, a shaft upon which said piston is mounted, said piston and said casting each having a pair of spiral faces and beveled faces connecting the same, all faces of said casting being perforated, means for permitting the expanding gases to pass through the perfaces'extending through a relatively forations in the beveled faces of said casting, and means permitting the exhaust gases to pass through perforations in the spiral faces of said casting.

2. A gas engine comprising a casting having spiral faces and beveled faces, a shaft, a rotary piston also having spiral faces and beveled faces, the spiral faces upon said piston being turned toward and being adapted to come into engagement with the spiral faces upon said casting, and an ignition chamber within the casting, the spiral faces of said casting being provided with perforations through which the exhaust gas is adapted to pass, and the beveled faces of said casting being provided with perforations through which the expanding gas is adapted topass.

3. A gas engine comprising a casting, means for dividing said casting into an ignition chamber and an exhaust chamber, said casting having spiral faces and beveled faces, a rotating piston having spiral faces and beveled faces similar to the faces upon said casting, the spiral faces of said casting being provided with perforations through which the exhaust gas is adapted to pass, and the beveled faces of said casting being provided with perforations through which the expanded ignited gas is adapted to pass.

4. A gasengine comprising a casting having spiral faces and beveled faces, a rotating plston mounted thereupon having spiral faces and beveled faces, said faces upon the piston being turned toward the faces upon said casting, alpair of cams, one of said cams being fixed against rotation, said cams being also provided with spiral faces and with beveled faces extending through the same number of degrees of arc and being of the same pitch as the'corresponding faces upon said casting and said piston.

5. A gas engine comprising a casting, 1i-

vided into an interior ignition chamber and an exhaust chamber, said castin having spiral faces andbeveled faces, said large number of degrees of are and said beveled faces extending through a relatively small number of degrees of are, a rotating piston shaped similarly to said casting, the beveled faces of said casting being per orated,'means for admitting gas within the casting, the as being adapted to pass through sai perforations and bear upon said rotating piston, and a shaft upon which said piston is carried.

6. A gas engine comprising a casting having spiral faces and beveled faces, a shaft, a rotary piston also having spiral faces and beveled faces, each of said various spiral faces extending through the same number of degrees of-arc and being of the same pitch as every other spiral face, each of said spiral faces extending through a relatively spiral large number of degrees of arc and each of the beveled faces extending through a relatively small number of de ees of arc, an ignition. chamber within t 1e casting, and means for causing the expansive force of the gas to be exerted upon said rotating piston.

7. A gas engine comprising a casting having spiral faces and beveled faces, a shaft, a rotary piston also having spiral faces and beveled faces, the spiral faces upon said piston being turned toward and being adapted to come into engagement with the spiral faces upon said casting, and an ignition chamber within the casting, the beveled faces of said casting being provided with perforations through which the ignited gas is adapted to pass, said spiral faces extending through a relatively lar e number of degrees of arc and said bevele faces extending through a relatively small number of degrees of arc.

8. A gas engine comprising a casting, means for dividing said casting into an ignition chamber and an exhaust chamber, said casting having spiral faces and beveled faces, and a rotating piston having spiral faces and beveled faces similar to the faces upon said casting, the beveled faces upon the casting being provided with perforations through which the ignited gases are adapted to pass,'sa-id spiral faces extending through a relatively large number of degrees of arc and said beveled faces extending through a relatively small number of degrees of arc.

9. A gas engine comprising a casting, means for dividing said casting into an ignition chamber and an exhaust chamber, said casting having spiral faces and beveled faces, and a rotating piston havin spiral faces and beveled faces similar to tie faces upon said casting, the spiral faces of said upon the piston being turned toward and being adapted to come into engagement with the spiral-faces upon the casting, said spiral faces differing in length, in pitch, and in inclination from the beveled faces, an ignition chamber within the casting, and means for causing the piston to compress the gases within the ignition chamber when the beveled faces upon the piston are in engagement with the beveled faces upon the casting.

11. A gas engine comprising a casting having spiral faces and beveled faces, a shaft, a rotary piston also having spiral faces and beveled faces, the spiral faces upon the piston being turned toward and being adapted to come into engagement with the spiral faces upon. the casting, said spiral faces differing in length, pitch, and in inclination from the beveled faces, an ignition chamber within the casting, and means for causing the expansive force of the gas to be exerted upon the piston when the spiral faces are in engagement with the spiral faces upon the casting.

In testimony whereof, I have hereunto subscribed my name in the presence of two Witnesses.

GUSTAV GEHRANDT. Witnesses Rosa. Knorz, AUGUST WIn rnn, 

